James b



JAMES B. BEAN, OF BALTIMORE, MARYLAND, ASSIGNOR TO l-IIMSELE AND l A. H.BALDEBSTON, OF THE SAME PLACE.

Letters Pate-nt Na 68,548, dated September 3, 1867.

@he Sunnah tuant tu in iluso items utent mit mating mrt nf tige smut.

TO ALL WHOM IT MAY CONCERN:

Be it known that I, JAMES B. BEAN, of the city and county of Baltimore,and State of Maryland, have 'r invented a new and improved Method ofCasting Aluminium in fine moulds; and I do hereby declare the followingtobe a full, clear, and exact description of the same, suiiicient toenable one skilled in the art to which the invention appertains'to makeand use the same, reference being had to the accompanying drawings,forming part of this specification, in which- Figure 1 is a sectionalelevation through the line .c x, iig. 2.

Figure 2 is a plan or top view.

In this invention the metal is cast into fine moulds u nder pressure ofa high column of the metal itself, contained in a conduitof soapstone,earthenware, or other similar substance, heated to about the meltingpoint` of the metal cast. The moulds and conduit, at the moment ofcasting, are filled with hydrogen or other gas containing no oxygen.

In casting aluminium,'and several other metals possessing similarproperties, the great diiiculty has hitherto been the impossibilityof'producing a solid casting having all the details'of a fine mouldfaithfully represented. The source of this difficulty is mainly from theextreme lightness of the met'al'and the tough film which forms on thesurface of the melted mass as soon as cast. These two properties combineto prevent the melted metal from owing into the more minute details andparts of the mould, and at the same time prevent the'closing up offaults and air-cellsin the body of the casting. Aluminium especially,Ain its pure state, is so verylight, vand the film formed is so tough,as to render it practically worthless for casting by the old methods.

Still another trouble in casting any metal, but particularly annoying incasting aluminium, arises from its great contractibility in cooling, bywhich holes and imperfections in the surface of the casting occur,rendering it indispensable to success that means should be devised forcountcracting this eifect. i

In the invention hereafter to be described I propose to obviate allthese diiliculties by a process which I 'have been testing andperfecting for years, and which, I am able at last to say, renders thecasting of aluminium and other metals of kindred properties in finemoulds, forthe purposes of the dentist, the `jewcller, the artist,

i or any others who have to malte fine metallic castings, as easy anduniformlysuccessful as has been the casting of gold and silverheretofore.

In the drawings, A A represent a stand with a heavy base, having four.posts, a a a ct, projecting upward from it, two of the posts havingset-screws a passing through them. This device is for the purpose ofholding my flask, containing the mould, firmly in an upright position,and at the same time binding together the two halves of the mould. .B Brepresent. my flask, which I fix in the stand A, as shown in thedrawings. The outside flask is composed of two similar parts, B and B',one having two or three projections, I: b la, fitting into correspondingrecesses, or between pins b b b in the other, to-indicate the properrelative position of the parts 5 B and Bl to-each other. The two sides,BA2 and Bi, contain a number of holes, c c c e, for the purpose ofgiving vent to steam and gases that may accumulate in the interior ofthe mould. One of the sides, B3, is movable, for the purpose of lllingin the last portions of the composition forming the mould. Theprojections di di, on either side of the gate d, are pierced for thereception of the vents C C.

The flask thus formed contains within it 'a mould or matrix of thearticle to be cast. I make this mould of a compoundof about two parts,by weight, of powdered pumice-stone, and one part of fine calcinedplaster,l of Paris, mixed together with water to the consistency' ofcream or thin batter, and poured over the model Jf -the article to becast, in the manner usually practised in making such moulds in plasterof Paris.

Vent-s C C are placed on either side of the gate d, and communicate withthe interior cavity of thc mould at two of its highest points. Thesepermit the escape of the aeriform or gaseous contents of thc mould asthe metal fills it. I fill the outer portion of these vents, in themanner shown in the drawing, with/Small metallic rods or wires e e e,between which the air will escape readily, and which will yet preventthey escape of the melte'd metal, by cooling it so rapidly as to congealit by the time it has advanced half an infill 0l* more amOIlg ,f therods.

The melted metal is introduced to the mould through the high conduit D,composed off SOPBOHC earthen* Ware, or other substance equally capableof enduring the necessary heat, and not liable to contaminate the metalwith impurities. The conduit D is made in two parts: the lower, d, isfastened into the flasks D B1, as shown in the drawings, and the upper,cZ, which should be at least ten inches in length for aluminium, is madedetachable for the purpose of being heated separately, and also for thepurpose of emptying it of the melted metal contained in it after that inthe mould has become solid. The two parts are fitted together by theground-joint d.

The whole apparatus being thus constructed, it remains to show my methodof operating it. In the first place, I. expose the mould or matrix,together with the flask B B1, to a gentle heat, until it is completelydried andis heated to about 300D or 400 Fahrenheit, and thev point ofthe gate d is heated to redness. At the same time, the upper portion rlof the conduit D is uniformly heated to a point at or above the meltingpoint of the u metal to be used, and the metal itself, in sufficientquantity to till the mould and conduit, is heated to a degree somewhatabove its melting point. Before closing the mould, its interior surfaceis quickly heated to redness by the blow-pipe Haine.

The liask, containing the mould in its heated state, is now placed inthe stand or holder A, as shown in fig. 1, and the-set-screws tightenedto a proper degree. The vents C C, containing their bundles of littlerodse e, are now put, while cold, into their places on each side of thegate CZ, and the. upper portion of the conduit, heated as abovedescribed, is put in place and attached by means of the ground-joint al.v

I next ll the whole apparatus with common illuminating gas, hydrogen, orother gas entirely free from oxygen, by means of a pipe leading from.the source of supply of the gas and passing through a small plate ordisk of mica placed on the open end of the conduit, and the gas forcedinto the mould, issuing at the vents until all is completely filled. Thegas pipe and plate of mica are new quickly removed, and the molten metalpoured in without delay, quickly filling up the mould and conduit to thetop.

As soon as the metal has become solid in the mould,` and before it hascongealed in the conduit D, I detach the upper part d and let thenieltedmetal run out, for if allowed to become solid in the conduit,this portion of the apparatus might be destroyed in removing ittherefrom, or in subsequent manipulations of the iiask.

In this manner a solid and perfect casting can be made, not only fromaluminium, butfrom light and easily oxidized metals. The air beingunable tovcome in contact with'the metal in the mould, no oxide isformed on its surface, and under pressure of the high. column of fluidmetal, it flows rapidly and easily intoall the finest parts of adelicate mould, and brings out all the details of the design.

As the metal cools and contracts in the mould, by the pressure of thesuperposed molten metal in the conduit, it flows in and supplies thedeficiency until the casting is complete, .thus absolutely remcdying allthe evils of its great expansibility by heat. l

The pressure of the column of metal may be regulated at pleasure bymaking the conduit of a height proportionate to the specific gravity ofthe metal to be cast. Even silver and gold,and other heavy metals, arecastby means of this apparatus with much greater perfection than by theold methods.

The apparatus is simple, and easily worked, and, if the process abovedescribed be followed, is uniformly.

successful in producing most perfect castings, however delicate may bethe moulds.

Having thusdescribed my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. The iiask B D1, in combination with the frame or holder A, having theposts a e a aand the set-screws a" a', constructed as and for thcpurpose specified. 4 v

2. The flask B D1, having the vents C C and the gate cl, all constructedand arranged substantially as described.

3. Stopping the vents C C with the small rods ye e e, as and for thepurpose set forth.

4. The conduit D, composed of soapstone or other similar material, incombination with the gate d, as described.

5. I claim supplying fluid metal to compensate for the contraction ofthe metal in the mould, as well as to secure a denser casting, by meansAof the detachable' reservoir D, heated previous to pouring the metal,substantially as described.

G. Expelling the atmospheric air from the mould by meansof, andsubstituting therefor, a gas which is destitute of oriygen, in themanner and for the purpose set forth.

7. The iaslc B Bl, constructed, gated, and vented substantially asdescribed, in combination with an interior lining-composed ofpumice-stone and plaster of Paris, in proportions substantially as setforth. Y

' JAS. B. BEAN, D. D. S.

i Witnesses:

JAMES H. GRIDLEY, SoLoN C. Kanon.

